Field of the Invention
The present invention relates to a technique for registering an event associated with a network service.
Description of the Related Art
Conventionally, there is a technique for asynchronously receiving an event generated on a terminal on a network, such as WS-Eventing (Web Services Eventing). In this technique, the contents of an event desired to be received and an event transmission destination (URL as an event reception address) are registered in an event transmission source. After the registration has been performed in the event transmission source, when an event generated at the event transmission source is detected, the generated event is notified to the event transmission destination thus registered.
In Japanese Patent Laid-Open Publication No. 2007-257481, there has been proposed a technique in which a printing device counts the number of times of failure in communication from an event transmission source to an event transmission destination, and when the number of times of failure reaches a predetermined value, the event transmission destination is deleted from the registration. Further, as another technique, to protect the system from network attack from a remote apparatus, some systems are equipped with a personal firewall function for restricting network communication from the outside to a computer. Note that the personal firewall function includes a type which does not uniformly restricts communication from remote apparatuses, but allows configuration to permit communication from a specific IP address or port number.
Let it be assumed that an information processing apparatus equipped with the personal firewall function is a terminal that is registered as an event transmission destination, and asynchronously receives an event generated on a terminal on a network. In this case, there is a problem that an event transmitted from the terminal as an event transmission source, e.g. an image forming apparatus, is blocked by the personal firewall. For example, in a case where a port number for receiving an event is among communication restriction targets restricted by the personal firewall, the information processing apparatus cannot receive the event. However, the port number (URL) used for notifying an event was registered in the image forming apparatus as the event transmission source by the information processing apparatus as the event recipient, and event reception registration was successfully performed. Therefore, the situation is that the event recipient is expecting that the event will be notified.
That is, although each event is transmitted to an event receiving section of the information processing apparatus based on the event reception registration, the information processing apparatus is incapable of knowing that the event has been discarded by the personal firewall, and hence the information processing apparatus continues to wait to receive events which cannot be received. Further, this means, as a result, that the registration of reception of the event which cannot be received is uselessly performed. Note that in the case of the technique disclosed in Japanese Patent Laid-Open Publication No. 2007-257481, the printing device makes an attempt to transmit the event to the destination which cannot receive the event at least once before the destination of the event transmission is deleted from the registration, and hence this causes useless processing to be performed.